Welding Robots: Technology, System Issues and Applications'

Citation

Weston, J. and BEng, C.E.E. (2006), "Welding Robots: Technology, System Issues and Applications'", Industrial Robot, Vol. 33 No. 3, pp. 240-240. https://doi.org/10.1108/ir.2006.33.3.240.1

While this small volume contains much useful information it was not an easy read, probably because English is not the mother tongue of the authors. The book is presented in five major sectors: historical introduction to robotic welding, welding techniques, sensor systems, system issues and an application example.

In the introduction it says welding is “the most popular application of robots”, but fails to note that these applications are about 50:50 arc welding and resistance spot welding. This is important because the book focuses on the challenges faced when fully automating, using robots, the arc welding process. There is quite a good history of welding process development, but it does not link well to the theme of robot welding. This comment also applies to their history of welding process developments. Mention could have been made, for example, of the use of a Unimate robot for spot welding in the early 1960s, an AAB robot for arc welding in the mid‐1970s and more recently the synchronous motion control of 6 robot axes with two‐axis work piece manipulation. These were, I believe, significant developments. An interesting and complex robot cell is presented, and while the activities being performed are similar to those undertaken in some welding operations, deburring is the operation discussed.

Next there is a large section on welding processes. It covers those techniques where the robot has either manipulated the welding process or taken the work piece to the process tool. In this section the authors have concentrated on aspects of the process principles. More value might have been given by focusing on the challenges that are faced when these processes are combined with robot technologies. The methods of laser generation may be of interest but it is the process performance that challenges the robot welding system. For example, what do factors such as, the speed of welding, the small diameter and length of focus of the laser beam, the process tolerance and the safety requirements mean to the system integrator?

The section on sensors for welding robots rightly focuses on the important vision and arc parameter (through the arc) based techniques. There is also quite a lot of information on the monitoring (sensing) and control of the gas metal arc welding (GMAW) process. However, some issues are not well addressed, e.g. the need to monitor GMAW information to meet quality assurance procedural requirements, or other sensor types, which might be used to ensure piece part presence or location.

In the chapter on system issues the integration of a GMAW robot system are covered. That is, the process model, the sensor system, the robot(s) and the outside world, that provides task information. There is detail on remote procedure calls and TCP/IP sockets for communication and an indication of how programmes should be structured. This section would be of particular benefit to those developing similar integration.

The applications examples chapter describes laboratory studies that used a cell, based on ABB robot technology. The establishment of the links between 3D CAD, used for the component and cell designs, the cell and the modules within it are described. Also, examples are given of the code that was generated to link these various modules together. This section is perhaps the strength of the book.

This is a book to be dipped into and will be of greatest use to researchers and those integrating welding cells.